Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: Metal fence as counterpoise  (Read 2011 times)
WK5H
Member

Posts: 111




Ignore
« on: January 22, 2010, 10:54:13 AM »

If things go well, I will be moving into town in June with my then to be wife.

I currently live in the country, and have room for an 80M loop.  I'm quite happy.

In town, it's a different story.

The only trees are the ones overhanging from the neighbors into the backyard, and only one of them is quite tall, around 50ft or so.

There is a metal fence on 2 of the 3 sides of the backyard.

I have thought about installing a good quality vertical just above the fence line, and using the fence as radials/counterpoise.  Can this be done efficiently, or do I need to study more?

There's no antenna restriction in the neighborhood, but, I would like to keep the visualization of antennas down to a minimum.
Logged
WX7G
Member

Posts: 5970




Ignore
« Reply #1 on: January 22, 2010, 11:22:07 AM »

The metal fence will work as a counterpoise. Much of the return current will occur through earth and reduce efficiency but it will still work.

There are many quality verticals to chose from starting with the inexpensive Hustler 4BTV at $125 and going to over $400 for some of new offerings.
Logged
WK5H
Member

Posts: 111




Ignore
« Reply #2 on: January 22, 2010, 11:26:17 AM »

I have been looking at a few of those, and so far, one of the better with more good reviews than bad, is the DXE-MBVE-1 from DX Engineering.  I suppose if I purchased that, I could still use the fence as one big radial?
Logged
WB5JEO
Member

Posts: 805




Ignore
« Reply #3 on: January 22, 2010, 12:16:08 PM »

I've never seen anyone reporting any very critical evaluation of a metal fence as a radial system. My feeling is that it's probably not the same as just two long radials from the base of a ground mounted antenna. If I had to guess, I'd guess that it's better than just the two random length wires on account of the metal mass but that there's still a good bit of ground loss before return, because it's intercepting relatively little of the near field radiation and isn't resonant. Some have proposed that there would be some good in also running insulated wires just above the fence, but I doubt you'd ever get them anything like tuned, because of the close proximity to the metal fence, and I think it would be electrically pretty much the same as the fence alone. But it for sure beats no radials and will work (I've done worse to 4BTV's over the years), and it's far better than the ill-conceived installation you sometimes see tried, with the antenna mounted on a short support like a fence and a ground lead run down to a radial system on the ground, something that creates a bizarre sort of antenna when the ground lead radiates.
Logged
K7JQ
Member

Posts: 333




Ignore
« Reply #4 on: January 22, 2010, 01:01:26 PM »

I've used a screwdriver antenna mounted on a steel fence that was 70 feet long and 6 feet high, and it resonated (SWR 1.3:1 or less) well on all bands 10-80 meters (using a shunt coil for 40 and 80). It worked well for it's compromise, although I believe the radiation pattern was distorted as compared to many radials laid out in a spoke-like fashion.
Logged
K4JC
Member

Posts: 76




Ignore
« Reply #5 on: January 25, 2010, 04:53:17 PM »

I have a Hustler 6BTV using the metal fence as the counterpoise. It has worked way beyond my expectations! Since April 2009 I have worked all states and over 150 countries, mainly on 40 and 20 meters. There may be some distortion in the radiation pattern (at my antenna the fence runs basically east-west) but I haven't noticed any significant directionality.
Logged
WA7NCL
Member

Posts: 625




Ignore
« Reply #6 on: January 26, 2010, 02:36:58 PM »

I've used them and it can work.  

Consider using an autotuner and length of wire set up as a vertical or inverted L to the tall tree.  It's stealthy and the autotuner can be made to match the wire on many bands.  The fence can provide the ground for the auto tuner.  On the lower bands it will outperform the vertical if the wire is long enough.  Most verticals are heavily loaded below 30 meters.
Logged
KP2Z
Member

Posts: 48




Ignore
« Reply #7 on: January 26, 2010, 06:08:32 PM »

"I currently live in the country, and have room for an 80M loop. I'm quite happy."

So stay in the country and have her move out to you. Your not even married yet and she has you moving out of where your happy. Also sounds like she doesn't wish to see any antennas where your moving to.
Soon she will have you in the basement or the closet working QRP!

Sorry, I just could not resist. However, clothed in humor may be some truth.

Best of luck with your new life and new wife.

Tony - KP2Z
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!